DDX4 and male infertility: Transcriptomic changes triggered by RNA helicases initiate differentiation processes and result in a development of cell lineages (Medrano et al. 2012; Ramathal et al. 2015) Below, we describe examples of DEAD-box helicases: DDX3Y, DDX25, and DDX4/VASA in contexts of germline generation, spermatogenesis, and male infertility.